CH 3: Managing Local Users and Groups

Question 1

useradd

• c
• g
• G
• a
• d
• m
• s
• L
• U

Answer 1

• c add commont to the account such as real name
• g: specify the primary group
• G: specify a comma-separated secondary groups
• a: append, use this with -G to add secondary groups
• d specify a particulary home dir for account
• m move users home directory to a new location
• s: specify a login shell
• L: lock the user account
• U: unlock user account

Question 2

difference between userdel and userdel -r

Answer 2

using the -r removes the user from /etc/passwd as well as deletes home directory

Question 3

default ranges of UIDs/GIDs

Answer 3

0 is root
1-999 is for the system
1000+ is for local users
defined in /etc/login.defs

Question 4

create a regular group

create a system group

Answer 4

groupadd new_group. (GID will be >1000)

groupadd -r new_sys_group (GID will be <1000)

Question 5

delete a group

Answer 5

groupdel group_name

Question 6

modify a group such as changing the name

Answer 6

groupmod -n new_name old_name

Question 7

configuring password age with chage

• m 2
• M 90
• W 7
• I 14

Answer 7

• m 2 means min password age until it can be changed
• M 90 means password can be max 90 days old
• W 7 means warn 7 days before Max PW age
• I 14 means set the account disabled after 14 days

Question 8

set users account to expire in 45 days

Answer 8

date -d “+45 days” + %F
2020-10-25

then run: chage -E 2020-10-24

Question 9

Expire a user account

Unlock a user account

prevent a user from logging in

Answer 9

usermod -L

usermod -U

usermod -s /sbin/no login

Question 10

set password to expire immediately

Answer 10

chage -d 0 user

Question 11

view password/account expiry info

Answer 11

chage -l username

Question 12

set new accounts expiry info automatically

Answer 12

modify PASS_MAX_DAYS in /etc/login.defs

Question 13

show all groups a user is a member of

Answer 13

lid

Question 14

show all members of a group

Answer 14

lid -g